Why Hammerhead Sharks Have Weird-Shaped Heads

The hammerhead shark is one of the ocean's most recognizable creatures — but its bizarrely shaped head (called a cephalofoil) isn't just for looks. It gives the hammerhead extraordinary sensory abilities and makes it one of the ocean's most effective predators.

Why Is a Hammerhead's Head Shaped That Way?

The wide, flat head spreads the shark's sensory organs across a larger area. Sharks have electroreceptors called ampullae of Lorenzini that detect the electric fields of prey. The hammerhead's wide head allows it to detect prey buried in sand that other sharks would miss entirely. Its eyes are also placed far apart, giving it near-360-degree vision.

What Do Hammerhead Sharks Eat?

Hammerheads are famous for hunting stingrays. They pin rays to the seafloor with their hammer-shaped head and are completely immune to stingray venom. They also eat fish, squid, octopuses, and other sharks. One great hammerhead was found with 96 stingray barbs in its mouth — still alive and well.

Are Hammerhead Sharks Dangerous?

Hammerheads are responsible for very few attacks on humans. Great hammerheads are shy and tend to avoid divers. Despite being large (up to 20 feet), they are considered low risk to humans compared to great white, bull, and tiger sharks.

Are Hammerhead Sharks Endangered?

Sadly, yes. The great hammerhead is listed as Critically Endangered — it has declined by over 80% in recent decades due to fishing pressure. Their fins are highly prized for shark fin soup, and they are slow to reproduce. They are also sold as "flake" fish in fish and chips without consumers knowing.

Amazing Hammerhead Facts

• There are 10 species of hammerhead shark, ranging from 3 to 20 feet long.
• They have been documented swimming in schools of hundreds during migration.
• Female scalloped hammerheads can reproduce without a male — via parthenogenesis.
• Their swim dorsal fin sticks out of the water, making them look like a classic movie shark.